The extracellular matrix is essential for the integrity of the lung and when disrupted can lead to the architectural changes seen in emphysema. The etiology of emphysema is believed to be due to an imbalance in the proteases and antiproteases within the lung. Studies have focused on elastolytic enzymes as the primary agents in disease pathogenesis, however, recent data suggest that collagenases may also be involved in the destruction of lung tissue in emphysema. It is hoped that this expanded understanding of the pathophysiology of emphysema will lead to improved therapy in the treatment of the disease.